Piston valve engine



Jan. 18, 1938.

J. W. JENKINS PISTON VALVE ENGINE Filed May 18, 1954 5 Sheets-Sheet 2 FIG. 1.

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' v l PIsToN VALVE ENGiNE AFiled. May 18, 1954 3 ASheelj-Sheet .3

Patented Jan. 18, 1938 umn-au s'rA'ras PATENT OFFICE l laim.

The invention relates to explosive engines and more particularly to explosive engines having inlet and outlet ports opened and closed by a slidingelement.

It is an object of the invention to provide in combination with an explosive engine having a.

ported cylinder closed at one end and open at the other, a piston-like valve element which serves to close and open the cylinder ports in proper v l time and which serves as a removable closure for the closed end of such cylinder.

It is a primary object of the invention to provide in combination with an explosive engine having a ported cylinder with a closed end and id an open end, a slidable valve element which serves as a closure for the closed end of said cylinder, and to provide means for actuating said element to a more retrograde position during the .intake stroke than in the compression and o power stroke, and correspondingly increasing the 35j said cams considered cubical size of the combustion chamber of the engine during the intake stroke, for entering correspondingly larger -fuel charges within the cylinder.

It is an important object of the invention to provide for operating such slide element, two substantially equal and co-axially related peripheral cams secured side by side to a shaft in complementary relation to each other, each of said cams having a true circular face portion, each having a depressed face portion angularly spaced from the other about the shaft,leach having a protruding face portion angularly spaced about the shaft, the diametrical vertical distance across together from any peripheral point of one cam to the most distant peripheral point of the other being equal at all peripheral points of either cam; and a cam follower secured to said elements and having a. cam seat between said valve element and said shaft, said seat following the peripheral face of one cam, and another cam seat on the other side of said shaft following the peripheral face of the lother cam, said cams operating to hold said valve element in fixed position through said follower substantially during the nominal -compression and power strokes of the engine, and operating to move said valve element to cover the exhausst port and open the inlet port of the engine durwing the nominal intake stroke thereof, and operating to move said valve element to cover the intake port and uncover the exhaust port dur ing the nominal exhaust stroke of the engine.

It is a further object to carry the valve for 55 the ignition spark plug in operating position with said element, and to provide a threaded hole therethrough for engaging such plug; and Ato provide a flexible and stretchable conductor between the terminal connection of such` plug, and a relatively fixed terminal, said conductor yielding to the movements of said valve element.

The above and other objects are attained by the structure illustrated in the accompanying drawings inwhich:

Figure 1 is a cross-sectional view of the invention taken in the proximity of line l-l of Fig. 5; and in which the engine parts are shown in intake position; v

Fig. 2 is a View similar to Fig'. 1 showing the engine parts in compression position;

Fig. 3 is a sectional viewJ taken in the proximityA of line 3--3 of Fig. 5 and shows the engine parts in power stroke position;

Fig. 4 ls a View similar to Fig. 3, showing'the engine parts in exhaust stroke position;

Fig. 5 is a partial fragmentary side view ofy the engine partly in section;

Fig. 6 illustrates the gearing through which the valve element cams 'are operated from the engine crank shaft;

, Fig. 7- is a detailed sectional fragmentary View of the engine cam and follower mechanism; and,

Fig. 8 is a cross sectional View taken in the proximity of line 8-8 of Fig. 4.

The example of the invention herein described so. 'is embodied in a vertical explosive engine.

Similar characters of reference designate similar parts throughout the several views. Referring to Figure l, the numeral l designates the engine crank case in which the crank shaft 2 is journaled. The cylinder 3 in this example of the invention is integrally merged at its inner end with said crank case, the piston being slidably'disposed therein, and being associated with said crank shaft through the usual connecting rod 5.

0 Beyond the other or outer end of said cylinder the cam shaft 6 is journaled substantially at right angles to the longitudinal center line of said cylinder, by the bearings 1 best shown in Fig. 5. Still referring to Fig. 5 and also Fig. 6 it wm be under- 45 stood that said cam shaft is rotated by the crank shaft 2 through the sprocket chain 8, said chain meshing with the crank shaft carried sprocket 9 and the cam shaft sprocket ill, said sprockets being of suitable ratio to gear the camshaft down 50 to half the speed of the crank shaft, as will be understood by those familiar with four-cycle explosive engines.

At the intersection of the cam shaft t with the II and I2 are .formed side by side on said cam shaft. Said cams have .continuous peripheral cam faces, and the cam I I has a true circular face portion I3, in rotary advance of `the similar circular face portion 'I4 of the cam I2, as rotated in the direction indicated by the arrow` I5 of Figure l. The protruded face portion I6 of the cam II immediately follows the true circular portion I3 thereof, but the depressed face portion I1 of the cam I 2 immediately follows the true circular portion thereof; and the true circular portion I3 of the cam II immediately follows the depressed portion I 8 thereof, while the true circular portion I4'of the cam I2 immediately follows the protruding portion I9 thereof, by which features said cams may be said to be in overlapping complementary arrangement as considered in Figure 1; and it is further pointed out that the vertical height measured from the lowest point on either cam to the highest point on the other cam, is the same in any rotated position of said cams.

On the cylinder side of the cam I I the cam seat 20 of the cam follower 2| rides said cam, said seat being substantially horizontal in this example of the invention, and the seat 22 of said follower rides the cam I2 on the other side of the cam shaft 6 from the seat 20, said seats being substantially parallel, the head 23 of said follower encircling said cam shaft. Follower guide pins 2li extend from the cylinder 3 parallel to the longitudinal center line thereof, said guides engaging the slides 25 of said cam follower, by which feature it will be understood that rotation of said cams against said cam seats will move the follower 2| on said guides, the movements of said follower being `co-directional with the movements of the piston fi; and said seats being substantially parallel, and said. cams together being the same distance across, it will be obvious that all positions of said follower are positively determined in both directions by said cams.

In the outer end of the cylinder 3 the pistonlike valve element 26 is slidably disposed, the outer end of said element being integrally. connected to the cam follower 2l, by which arrangement said valve element is operated in alternate,

y retrograde and return movements in said cylinder.

Beyond the path of the piston 4 from the crank shaft 2, the inlet port 21 is formed through the cylinder wall structure, Said port communicating with the carbureter -28 through the inlet manifold 29, and serving to close and open said port in required sequence as will be understood.

The lvalve element 26 is of somewhat inverted cup character, a web being formed across the lower end of` same, andv consisting of two iioor portions 30 and 3I, the floor portion 30, merging with the inlet-port closing side of said valve element and the floor portion 3I being oilset outwardly from the portion 30 and being united therewith by a more vertical wall 32, which with the more adjacent wall portion 33 of said element 'formsa channel on the inner side of said web,

which communicates with the port 34 formed through the wall portion 33, said port being adjacent to the inner surface of the floor portion 3 I.

On the opposite side of the cylinder 3, from the inlet port 21, said cylinder forms the exhaust port 35 through its wall structure, said exhaust port being more outwardly positioned in said cylinder than said inlet port, and being suitably located to register with the port 34 of the valve element 26 when said valve element is slid by the cams II and I2,-through the .follower 2| to the end of its return movement, and when said inlet port is covered by said valve element.

In Figure l, which illustrates the intake stroke of the engine, the valve element 26 is shown in its most outer position, the inlet port 21, being entirely uncovered by said valve element and the exhaust port 35 being covered by the wall portion 33 of said element, said element being conned to position upwardly by confinement of the cam seat 22 against `the most protruded point of the cam I2, and downwardly by confinement of the valve seat 22 against the most depressed point of the cam II, and Asaid element being thus precisively positioned against movement in either di-4 rection other than as determined by the rotation of said cams.

In Figure 1, the piston 4 being in downward travel, is shown at approximately halfway through the intake movement, the crank arms 36 of the crankshaft 2, being in approximately horizontal position. As said piston and crank move to their most downward position (not illustrated) or approximately the end of the intake stroke, the cams Il and I2 are rotated bythe crank shaft 2, through the sprocket chain 8, bringing the circular portion of the cam I I in engagement with the seat 20, and the circular portion of the cam I2 in engagement with the seat 22 and the valve element 26 being correspondingly lowered into ,inlet port-closing position, it being understood that at all intermediate points, said seats follow said cams with precision and without any so-called lost motion or back-lash.

As the crank arms 38 rotate'further to approximately horizontal position on the other side of the crank shaft as illustrated in Fig. 2 the piston 4 is correspondingly moved outwardly through approximately half its compression movement, the circular portions of said cams running in engagement with said seats respectively, and thus maintaining" the port-closing position of the .valve element while the piston approximately reaches the end of its compression movement, at which time thel compressed charge is ignited by the spark plug 31, which is threaded through the web oor 30 of the valve element 26, the ignition current being supplied and regulated by any suitable engine current source and timing means (not shown) The spark plug 31 is suiciently tall to support its terminal connection 38 higher than the upper edge of the valve element 26, by which feature it is convenient to connect said terminal connection with lthe fixed terminal 39, by the flexible ,the end of the power stroke, or approximately when the piston again reaches the end of its return stroke at about which time the depressed portion I1 0f the cam I2 isv rotated into contact with the cam seat 22 and the protruded portion I6 of the cam II is rotated into contact with the seat 20, causing the valve element 26 to move inwardly until the valve element port 34 registers lwith the cylinder exhaust port 35 initiating arcanes the exhaust stroke, bestiliustrated in Fig. 4, the exhaust fumes passing through the ports 38 and 35. into the exhaust manifold 42, and as the piston again approximately reaches its most retrograde position, the cams are rotated to position preliminary to inlet stroke position as best illustrated in Figure 1.

A number of cylinders may be embodied in an engine as will be obvious from Fig. 5, each cylinder being provided with a valve element, cam follower, set of cams, etc. as above described.

In this example of the invention the upper end of the cylinder consists of a removable extension d3 which is bolted or otherwise secured to the cylinder proper, and the cylinder bore. isreduced in diameter through said extension, although it is understood that the cylinder may be an integral part throughout its length, and have the same bore diameter throughout its length, under which conditions the valve element and piston are oi the same diameter.

It will beobserved that the valve element 2B is in higher position during the intake stroke illustrated in Figure 1, than'in the compression and power strokes as illustrated in Fig. 2, and Fig. 3, respectively, by reason of which the combus- 'tion chamber port Sd of the cylinder 3 is of greater cubical size during the intake stroke, thus increasing the intake capacity of the cylinder Without decreasing the compression pressure carried out in the compression stroke.

It is understood that during the compression and power stroke of the engine the pressure per square inch within the cylinder is exerted against the valve element 26 and that said valve element is heldin place against such pressure by the cam il; and that in the intake or suction stroke of the engine the suction pull exerted on said valve element is `resisted by the cam i2.

Referring to Figures 1 to 5, the pistonrings 45 and 46 are provided in the corresponding grooves o! the valve `element 23, the upper ones d6, of said rings being of a standard width. but the lower rings being of greater vertical width than the corresponding dimension of the ports 21 `and 35, by which feature said lower rings are adapted to slide over said ports without expanding into same and disabling the engine, it being understood thatlthe rings which pass over said ports are of greater vertical width than the corresponding width of the ports.

While the description and drawings illustrate in a general way a certain mannerl of carrying the invention into effect, it is obvious that many modications may ,be made `Ain the various details Without departing from the scope of the appended claim,- it being understood that the invention is not restricted 4to the particular example herein shown.

The invention claimed-is:

.A gas engine comprising a cylinder having an open upper end and inlet and exhaust ports, a

vsliding valve within the open end of the cylinder and closing the same and controlling the inlet and exhaust ports. a rigid member carried by the valve and extending beyond the cylinder, said rigid member'being smaller in cross section than said valve member and having an outer end provided with a transverse opening, said opening having cam contacting surfaces and cam clearing surfaces, a driven shaft passing through said opening, 'cams carried by the shaftand engaging said cam contacting surfaces to impart proper movement to the valve, a means extending rigidly from the cylinder, said means slidably engaging said enlarged outerend` of said central member at a sufficient distance from the cylinder and sliding valve to prevent overheating at such engagement andto facilitate the convenience oi lubrication, repair and other attention of same vindependently of the cylinder and valve proper. said means preventing-.rotation of said valve by the friction 'of said cams against saidvcam con- 

